FIELD OF THE INVENTION
[0001] The present disclosure relates to a water delivery apparatus for use at a household
appliance. The present disclosure also relates to a household appliance comprising
a water delivery apparatus and a steam generating unit.
BACKGROUND OF THE INVENTION
[0002] In many currently known household appliances which involve the use of water or steam,
such as coffee appliances, steam cleaners, irons with steam generators, a water reservoir
and a water pump are provided for the purpose of controlling and directing a water
flow within the appliance. The water pump provided in these appliances is typically
a solenoid pump which typically adds to the costs of manufacture and maintenance.
Moreover, most of the water pumps (e.g. solenoid pumps) currently used in these household
appliances make undesired noise during operation.
SUMMARY OF THE INVENTION
[0003] As noted above, there are a number of disadvantages associated with the currently
available water delivery techniques used in household appliances, such as high manufacturing
and maintenance costs associated with the use of water pumps and/or unwanted noises.
It would therefore be advantageous to provide an improved water delivery apparatus
for use at a household appliance which address these disadvantages.
[0004] To better address one or more of the concerns mentioned earlier, in a first aspect,
a water delivery apparatus for use at a household appliance is provided. The water
apparatus comprises: an air-tight water storage unit configured to store water; an
air channel configured allow air to enter the water storage unit at a predetermined
height level so as to regulate the water pressure in the water storage unit; and a
water delivery tube comprising a first end and a second end, wherein the first end
is connected to the water storage unit, and the second end is connected to a component
of the household appliance at which water is utilized for performing a function of
the household appliance. The water delivery tube is arranged such that its second
end is lower than the predetermined height level, and the height difference causes
water to flow from the water storage unit to the component of the household appliance,
and the rate of water flow from the water storage unit to the component is based on
at least one of: the extent of the height difference, the inner diameter of the water
delivery tube, and the length of the water delivery tube.
[0005] In some embodiments, the water delivery apparatus may further comprise a flow adjustment
unit arranged at the water delivery tube. The flow adjustment unit may be further
configured to reduce or increase the inner diameter of at least a part of the water
delivery tube. In these embodiments, the flow adjustment unit may comprise a restriction
element having an orifice, the orifice having a smaller diameter than the inner diameter
of the water delivery tube. Therefore the rate of water flow from the water storage
unit to the component may be further based on the dimensions of the restriction element
(which controls the inner diameter of the water delivery tube.
[0006] In some embodiments, the water delivery tube may be configured such that its length
can be adjusted.
[0007] In some embodiments, the water delivery apparatus may further comprise a control
unit configured to adjust, based on a user input, at least one of the diameter of
at least a part of the water delivery tube and the length of the water delivery tube.
[0008] In some embodiments, the air channel may be a hollow tube vertically arranged at
the water storage unit, the hollow tube having a top end located external to the water
storage unit and a bottom end arranged to be submerged in the water stored in the
water storage unit, and the height difference between the bottom end of the hollow
tube and the second end of the water delivery tube causes water to flow from the water
storage unit to the component of the household appliance. In these embodiments, the
water storage unit may further comprise: a top opening through which the hollow tube
is arranged, and an air-tight covering element arranged to cover the top opening.
Furthermore, in these embodiments, the water delivery apparatus may further comprise
an air valve arranged at the top end of the hollow tube configured to selectively
allow air flow such that water flow via the water delivery tube can be initiated or
stopped. The air valve may be a manually or electronically operable control valve
which can be controlled to vary the size of its air flow passage. Also, the air valve
may be configured to be controlled by actuation of an actuation unit.
[0009] In some embodiments, the air channel may be a level chamber arranged adjacent to
the water storage unit. The level chamber may be connected to the water storage unit
through a shared opening and the first end of the water delivery tube is connected
to the level chamber, wherein the height difference between the shared opening and
the second end of the water delivery tube causes water to flow from the water storage
unit to the component of the household appliance.
[0010] In a second aspect, there is provided a household appliance comprising: the water
delivery apparatus as described herein, and a steam generating unit, wherein the steam
generating unit is the component of the household appliance at which water is utilized.
In some embodiments, the household appliance may be a steam iron.
[0011] According to the aspects and embodiments described above, the limitations of existing
techniques are addressed. In particular, the above-described aspects and embodiments
enable efficient and cost effective water delivery functionality to be realized within
a household appliance without creating unwanted noise during operation of the household
appliance. There is thus provided an improved water delivery apparatus and a household
appliance comprising a water delivery apparatus.
[0012] These and other aspects of the disclosure will be apparent from and elucidated with
reference to the embodiment(s) described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a better understanding of the embodiments, and to show more clearly how they
may be carried into effect, reference will now be made, by way of example only, to
the accompanying drawings, in which:
Fig. 1 is a block diagram of a water delivery apparatus according to an embodiment;
Fig. 2 illustrates a water delivery apparatus and a component at a household appliance,
according to an embodiment; and
Fig. 3 illustrates a water delivery apparatus according to another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] As noted above, there is provided an improved water delivery apparatus and a household
appliance which address the existing problems.
[0015] Fig. 1 shows a block diagram of a water delivery apparatus 100 according to an embodiment,
which can be implemented at a household appliance that makes use of water and/or steam
in its typical functions, such as coffee appliances, steam cleaners, irons with steam
generators, etc. The water delivery apparatus 100 comprises a water storage unit 110,
an air channel 120, a water delivery tube 130, a flow adjustment unit 140, and a control
unit 150. The water storage unit 110 is an air-tight container configured to store
water. In some embodiments, the water storage unit 110 may be connected to a water
supply.
[0016] The air channel 120 is configured to allow air to enter the water storage unit 110
at a predetermined height level so as to regulate the water pressure in the water
storage unit 110. In some embodiments, the air channel may be hollow tube. An example
of these embodiments is illustrated in Fig. 2. In these embodiments, the hollow tube
may be vertically arranged at the water storage unit 110. The hollow tube may have
a top end located external to the water storage unit 110 and a bottom end arranged
to be submerged in the water storage in the water storage unit 110. Moreover, in these
embodiments, the water storage unit 110 may comprise a top opening through which the
hollow tube is arranged, and an air-tight covering element (e.g. a lid) arranged to
cover the top opening of the water storage unit 110.
[0017] In some alternative embodiments, instead of a hollow tube, the air channel may be
a level chamber arranged adjacent to the water storage unit 110. An example of these
embodiments is illustrated in Fig. 3.
[0018] The water delivery tube 130 is configured to deliver water from the water storage
unit 110 to a component of the household appliance at which water is utilized for
performing a function of the household appliance. For example, the component maybe
a steam generating unit (e.g. a heating plate) at a steam iron. The water delivery
tube 130 comprises a first end and a second end, the first end being connected to
the water storage unit 110 and the second end being connected to the component at
which water is utilized. In some embodiments where the air channel is implemented
as a level chamber, the first end may be connected to the water storage unit 110 through
the level chamber. In other words, the water stored in the water storage unit 110
may enter the level chamber before being delivered through the water delivery tube
130 to the component of the household appliance.
[0019] As will be explained in more detail with reference to Fig. 2 and Fig. 3, the water
delivery tube 130 is arranged such that its second end is lower than the predetermined
height level at which the air channel 120 allows air to enter the water storage unit
110. This height difference between the predetermined height level at which the air
channel 120 allows air to enter the water storage unit 110 and the second end of the
water delivery tube 130 would cause water to flow, by gravity, from the water storage
unit 110 to the component of the household appliance. In this case, the rate of water
flow from the water storage unit 110 to the component is based on at least one of:
the extent of the height difference, the inner diameter of the water delivery tube
130, and the length of the water delivery tube 130.
[0020] To demonstrate how the rate of water flow from the water storage unit 110 varies
based on the factors as mentioned above, an experiment was conducted in which three
different water delivery tubes having different lengths and height differences (between
the second end of the water delivery tube and the predetermined height level at which
the air channel allows air to enter the water storage unit) are used in conjunction
with a water reservoir. Specifically, in the experiment, the first end of a different
water delivery tube is connected to the bottom of the water reservoir each time, and
rate of water flow out of the second (open) end is measured. In this case, the difference
in height between the water level in the water reservoir and the second end of the
water delivery tube is regarded as equivalent to the height difference between the
predetermined height level at which the air channel 120 allows air to enter the water
storage unit 110 and the second end of the water delivery tube 130 of Fig. 1. The
measured water flow rates are delineated in Table 1 below.
Table 1 - Results of the experiment using water delivery tubes in different set-ups.
| Water delivery tube # |
Height difference (mm) |
Length of the water delivery tube (mm) |
Rate of water flow (ml/min) |
| 1 |
130 |
430 |
10 |
| 2 |
65 |
430 |
4.7 |
| 3 |
65 |
215 |
9.5 |
[0021] By comparing the results of water delivery tubes #1 and #3 in Table 1, it can be
appreciated that the larger the height difference between the water level in the water
reservoir and the second end of the water delivery tube, the higher the rate of water
flow in the water delivery tube. By comparing the results of water delivery tubes
#2 and #3, it can be appreciated that the shorter the length of the water delivery
tube, the higher the rate of water flow in the water delivery tube. Since the height
difference in this experiment (i.e. the height difference between the water level
in the water reservoir and the second end of the water delivery tube) essentially
provides the same effect as the height difference in the present embodiment (i.e.
the height difference between the predetermined height level at which the air channel
120 allows air to enter the water storage unit 110 and the second end of the water
delivery tube 130), it will be understood that the rate of water flow in the water
delivery tube 130 of the present embodiment can be controlled by controlling at least
one of: the extent of the height difference, the inner diameter of the water delivery
tube 130, and the length of the water delivery tube 130.
[0022] As described above, in some embodiments the air channel 120 may be a hollow tube
arranged vertically at the water storage unit 110. In these embodiments, the height
difference between the bottom end of the hollow tube and the second end of the water
delivery tube 130 would cause water to flow from the water storage unit 110 to the
component of the household appliance. In addition, in these embodiments, the water
delivery apparatus 100 may further comprise an air valve arranged at the top end of
the hollow tube configured to selectively allow air flow such that water flow via
the water delivery tube 130 can be initiated or stopped. The air valve may be manually
or electronically operable control valve which can be controlled to vary the size
of its air flow passage and/or to open and close. Also, the air valve may be configured
to be controlled by actuation of an actuation unit. For example, a button may be provided
at the top end of the hollow tube and upon actuation of the button the air valve may
be controlled (e.g. to open or close the valve).
[0023] As mentioned above, in some embodiments the air channel may be a level chamber arranged
adjacent to the water storage unit 110. In these embodiments, the level chamber may
be connected to the water storage unit 110 through a shared opening, and the first
end of the water delivery tube 130 may be connected to the level chamber. In this
case, the height difference between the shared opening and the second end of the water
delivery tube 130 would cause water to flow from the water storage unit 110 to the
component of the household appliance by gravity.
[0024] In some embodiments, the water delivery tube 130 may be configured such that its
length can be adjusted. For example, the water delivery tube 130 may have a telescopic
configuration which can be manually operated so as to shorten or lengthen the water
delivery tube 130. As another example, the water delivery tube may comprise of a plurality
of inter-connectable tube parts and the number of tube parts may be selected based
on a desired length. It will be appreciated that other types of configuration may
be possible for implementing a length-adjustable water delivery tube.
[0025] The flow adjustment unit 140 is arranged at the water delivery tube 130, and is configured
to reduce or increase the inner diameter of at least a part of the water delivery
tube 130. In this embodiment, the flow adjustment unit 140 comprises a restriction
element 145 having an orifice, the orifice having a smaller diameter than the inner
diameter of the water delivery tube 130.
[0026] The control unit 150 is configured to adjust, based on user input, at least one of
the diameter of at least a part of the water delivery tube 130 and the length of the
water delivery tube 130. The user input may be received via a user interface provided
at the household appliance. In this case, the control unit 150 may be implemented
as a part of a control unit of the household appliance. In some embodiments, the user
input may indicate a usage mode of the household appliance. For example, a user may
press a button at the user interface of the household appliance indicating an "eco
mode" in which water consumption is intended to be lower than a normal operation mode,
and based on this input the control unit 150 may be configured to adjust (e.g. decrease)
the diameter of at least a part of the water delivery tube 130 so as to reduce the
rate of water flow in the water delivery tube 130. In some embodiments, the control
unit 150 may be configured to control the flow adjustment unit 140 in order to adjust
the diameter of at least a part of the water delivery tube 130.
[0027] Although it is described above that the water delivery apparatus 100 comprises a
flow adjustment unit 140 and a control unit 150, in alternative embodiments the water
delivery apparatus 100 may not necessarily comprise a flow adjustment unit or a control
unit. In particular, in embodiments where the water delivery tube 130 is implemented
such that it is length-adjustable, a flow adjustment unit may not be necessary. Also,
in some embodiments the household appliance may comprise a control unit, and the control
unit may be configured to perform the functions described above with respect to the
control unit 150. In these embodiment, the water delivery apparatus 100 may not necessarily
comprise a control unit.
[0028] It will be appreciated that Fig. 1 only shows the components required to illustrate
an aspect of the water delivery apparatus 100, and in a practical implementation,
the water delivery apparatus 100 may comprise alternative or additional components
to those shown.
[0029] Moreover, it will be appreciated that in some embodiments a household appliance may
be provided. The household appliance may comprise the water delivery apparatus 100
as described above. The household appliance may further comprise a component at which
water is utilized for performing a function of the household appliance. For example,
this component maybe a steam generating unit (e.g. a heating plate).
[0030] Fig. 2 illustrates a water delivery apparatus 200 and a component 50 of a household
appliance, according to an embodiment. In this embodiment, the water delivery apparatus
200 comprises a water storage unit 210, an air channel 220, a covering element 221,
an air valve 222, and a water delivery tube 230. The water delivery apparatus 300
is for use at a household appliance, such as a steam cooker, and the component 50
of the household appliance in this embodiment is a heating plate configured to generate
steam.
[0031] The water storage unit 210 and the air channel 220 in the present embodiment are
implemented as a water reservoir having a hollow tube (e.g. a straw) arranged vertically
at the water storage unit 210. The covering element 221 comprises an air-tight lid
that is configured to cover a top opening of the water storage unit 210 so as to maintain
a constant air pressure level inside the water storage unit 210. In some embodiments,
the covering element 221 may be configured to be removable from the water storage
unit 210 so that water can be introduced into the water storage unit 210 (for example,
manually by a user). The hollow tube 220 has a top end that is located external to
the water storage unit 210 and a bottom end arranged to be submerged in the water
stored in the water storage unit 210. Specifically, as shown in Fig. 2, the hollow
tube 220 has been inserted through an opening of the water storage unit 210 and an
aperture (not shown in the drawing) of the covering element 221 in an air-tight manner,
such that its top end is above the covering element 221 and its bottom end is under
the covering element inside the water storage unit 210. As will be described in more
detail in the paragraph below, air can enter the water storage unit 210 through the
air channel 220 so as to regulate the water pressure in the water storage unit 210.
Therefore, in this embodiment, the bottom end of the hollow tube corresponds to a
predetermined height level at which air is allowed to enter the water storage unit
210.
[0032] The air valve 222 is provided at the top end of the hollow tube 220, the air valve
being configured to selectively allow air flow between the interior of the water storage
unit 210 and the external surroundings of the water delivery apparatus 200. In the
present embodiment, when the air valve is open, the difference in air pressure between
the interior of the water storage unit 210 and the external surroundings would cause
air flow from the external surroundings into the water storage unit 210 through the
hollow tube 220. This air flow into the water storage unit 210 would in turn regulate
the water pressure in the water storage unit 210 such that water can flow from the
water storage unit 210 to the heating plate 50 via the water delivery tube 230 by
gravity. When the air valve is closed, no air flow is allowed between the interior
of the water storage unit 210 and the external surroundings, and consequently the
maintenance of the air pressure within the water storage unit 210 would prevent water
from flowing out of the water storage unit 210 via the water delivery tube 230. In
some embodiments, the air valve may be a manually or electronically operable control
valve which can be controlled to vary the size of its air flow passage and/or to open
and close. In some embodiments, the air valve may be configured to be controlled by
actuation of an actuation unit (e.g. a button provided at the air channel 220), e.g.
to open and close.
[0033] Similar to the water delivery tube 130 as described with reference to Fig. 1, the
water delivery tube 230 in this embodiment also comprises a first end and a second
end. The first end is connected to the water storage unit 210 and the second end is
connected to the heating plate 50 of the household appliance. As mentioned above,
in the present embodiment the bottom end of the hollow tube 220 corresponds to the
predetermined height level at which air is allowed to enter the water storage unit
210. It is further shown in Fig. 2 that the second end of the water delivery tube
230 lower than this predetermined height level. The height difference between the
bottom end of the hollow tube 220 and the second end of the water delivery tube 230
is labelled as
h1 in Fig. 2. This height difference
h1 causes water to flow from the water storage unit 210 to the heating plate 50 of the
household appliance by gravity. In more detail, in this embodiment water delivered
via the water delivery tube 230 is dripped onto the heating plate 50 such that steam
can be generated.
[0034] As explained above with reference to Fig. 1, the rate of water flow from the water
storage unit 210 to the heating plate 50 is based on at least one of: the extent of
the height difference
h1, the inner diameter of the water delivery tube 230, and the length of the water delivery
tube 230. Hence, the water delivery apparatus 200 can be designed and manufactured
in accordance to the specific requirements of the household appliance. Furthermore,
the water delivery apparatus 200 may further comprise a flow adjustment unit and/or
a control unit such as those described above with reference Fig. 1 so as to allow
dynamic adjustment of water flow within the household appliance.
[0035] Fig. 3 illustrates a water delivery apparatus 300 according to another embodiment.
In this embodiment, the water delivery apparatus 300 comprises a water storage unit
310, an air channel 320, a water delivery tube 330, and a covering element 315. The
water delivery apparatus 300 is for use at a household appliance, such as a steam
cooker.
[0036] The water storage unit 310 and the air channel 320 in the present embodiment are
implemented as a water reservoir having an adjacent level chamber. The level chamber
320 in this embodiment is arranged in a side-by-side arrangement such that it is connected
to the water storage unit 310 through a shared opening 325. In other words, the shared
opening 325 allows water and air passage between the water storage unit 210 and the
level chamber 320. The covering element 315 comprises an air-tight seal that is configured
to cover a top opening of the water storage unit 310 so as to maintain an air pressure
level inside the water storage unit 310. Since the air inside the level chamber 320
can enter the water storage unit 320 through the shared opening 325 to regulate the
water pressure inside the water storage unit 320, the shared opening 325 corresponds
to a predetermined height level at which air is allowed to enter the water storage
unit 310.
[0037] Similar to the water delivery tube 130 as described with reference to Fig. 1, the
water delivery tube 330 in this embodiment also comprises a first end and a second
end. As shown in Fig. 3, the first end of the water delivery tube 330 is connected
to the water storage unit 310 through the level chamber 320. In other words, water
from the water storage unit 310 can be directed into the water delivery tube 330 after
it enters the level chamber 320. Although not explicitly illustrated in Fig. 3, the
second end of the water delivery tube 330 is connected to a component of the household
appliance at which water is utilized for performing a function of the household appliance,
such as a steam generating unit.
[0038] As mentioned above, in the present embodiment the shared opening 325 between the
level chamber 320 and the water storage unit 310 corresponds to the predetermined
height level at which air is allowed to enter the water storage unit 310. It is further
shown in Fig. 3 that the second end of the water delivery tube 330 lower than this
predetermined height level. This height difference between the shared opening 325
and the second end of the water delivery tube 330 is labelled as
h2 in Fig. 3. This height difference
h2 causes water to flow from the water storage unit 310 (and the level chamber 320)
by gravity towards the component of the household appliance. In some embodiments,
the water delivered via the water delivery tube 330 may be dripped onto a heating
element such that steam can be generated.
[0039] As explained above with reference to Fig. 1, the rate of water flow from the water
storage unit 310 via the water delivery tube 320 is based on at least one of: the
extent of the height difference
h2, the inner diameter of the water delivery tube 330, and the length of the water delivery
tube 330. Hence, the water delivery apparatus 300 can be designed and manufactured
in accordance to the specific requirements of the household appliance. Furthermore,
the water delivery apparatus 300 may further comprise a flow adjustment unit and/or
a control unit such as those described above with reference Fig. 1 so as to allow
dynamic adjustment of water flow within the household appliance.
[0040] Although it is described above that the covering element 315 is an air-tight seal,
it will be appreciated that in some embodiments alternative types of arrangement(s)
may be implemented to provide the same function as the covering element 315. For example,
in some embodiments the covering element 315 may be a removable air-tight lid so that
water can be introduced into the water storage unit 310 (for example, manually by
a user)
[0041] There is thus provided an improved water delivery apparatus for use at a household
appliance. There is also provided an improved household appliance comprising a water
delivery apparatus and a component at which water is utilized for performing a specific
function (e.g. steam generation).
[0042] Variations to the disclosed embodiments can be understood and effected by those skilled
in the art in practicing the claimed invention, from a study of the drawings, the
disclosure and the appended claims. In the claims, the word "comprising" does not
exclude other elements or steps, and the indefinite article "a" or "an" does not exclude
a plurality. The mere fact that certain measures are recited in mutually different
dependent claims does not indicate that a combination of these measures cannot be
used to advantage. Any reference signs in the claims should not be construed as limiting
the scope.
1. A water delivery apparatus (100, 200, 300) for use at a household appliance, the water
apparatus comprising:
an air-tight water storage unit (110, 210, 310) configured to store water;
an air channel (120, 220, 320) configured allow air to enter the water storage unit
at a predetermined height level so as to regulate the water pressure in the water
storage unit; and
a water delivery tube (130, 230, 330) comprising a first end and a second end, wherein
the first end is connected to the water storage unit, and the second end is connected
to a component of the household appliance (50) at which water is utilized for performing
a function of the household appliance,
wherein the water delivery tube is arranged such that its second end is lower than
the predetermined height level, and the height difference causes water to flow from
the water storage unit to the component of the household appliance, and the rate of
water flow from the water storage unit to the component is based on at least one of:
the extent of the height difference, the inner diameter of the water delivery tube,
and the length of the water delivery tube.
2. The water delivery apparatus (100) according to claim 1, further comprising a flow
adjustment unit (140) arranged at the water delivery tube (130), the flow adjustment
unit being configured to reduce or increase the inner diameter of at least a part
of the water delivery tube.
3. The water delivery apparatus (100) according to claim 2, wherein the flow adjustment
unit (140) comprises a restriction element (145) having an orifice, the orifice having
a smaller diameter than the inner diameter of the water delivery tube (130).
4. The water delivery apparatus (100, 200, 300) according any one the preceding claims,
wherein the water delivery tube (130, 230, 330) is configured such that its length
can be adjusted.
5. The water delivery apparatus (100) according to any one of the preceding claims, further
comprising a control unit (150) configured to adjust, based on a user input, at least
one of the diameter of at least a part of the water delivery tube (130) and the length
of the water delivery tube.
6. The water delivery apparatus (200) according to any one of the preceding claims, wherein
the air channel is a hollow tube (220) vertically arranged at the water storage unit
(310), the hollow tube having a top end located external to the water storage unit
and a bottom end arranged to be submerged in the water stored in the water storage
unit, and the height difference between the bottom end of the hollow tube and the
second end of the water delivery tube (230) causes water to flow from the water storage
unit to the component (50) of the household appliance.
7. The water delivery apparatus (200) according to claim 6, wherein the water storage
unit (210) comprises:
a top opening through which the hollow tube (220) is arranged; and
an air-tight covering element (221) arranged to cover the top opening.
8. The water delivery apparatus (200) according to claim 6 or claim 7, further comprising
an air valve (222) arranged at the top end of the hollow tube (220) configured to
selectively allow air flow such that water flow via the water delivery tube (230)
can be initiated or stopped.
9. The water delivery apparatus (200) according to claim 8, wherein the air valve (222)
is a manually or electronically operable control valve which can be controlled to
vary the size of its air flow passage.
10. The water delivery apparatus (200) according to claim 8 or claim 9, wherein the air
valve (222) is configured to be controlled by actuation of an actuation unit.
11. The water delivery apparatus (300) according to any one of claims 1 to 5, wherein
the air channel is a level chamber (320) arranged adjacent to the water storage unit
(310), wherein the level chamber is connected to the water storage unit through a
shared opening (325) and the first end of the water delivery tube (330) is connected
to the level chamber, and wherein the height difference between the shared opening
and the second end of the water delivery tube causes water to flow from the water
storage unit to the component of the household appliance.
12. A household appliance comprising:
the water delivery apparatus (100, 200, 300) according to any one of the preceding
claims; and
a steam generating unit, wherein the steam generating unit is the component of the
household appliance at which water is utilized.
13. The household appliance according to claim 12, wherein the household appliance is
a steam iron.